BERLIN  The first wild bear seen in Bavaria in 170 years is believed to have returned to Austria after authorities gave hunters the green light to shoot the rampaging beast, the state's ministry said on Tuesday.

"There have been no sightings or signs of the bear today and local authorities believe that he has returned to Austria," said Roland Eichhorn, spokesman at Bavaria's Environment Ministry.

The young brown bear was welcomed when it wandered across the Austrian border over the weekend. But the 100-kilogram (220.5 lb) beast soon made headlines as an unwelcome guest after killing a dozen sheep and numerous chickens in its trail, prompting authorities to allow its killing.

"It is now a problem bear," Bavarian Environment Minister Werner Schnappaufsaid earlier on Tuesday. "A man-bear encounter could occur at any time. It cannot be allowed to roam freely. We will ask hunters to shoot the bear."

The ministry said Austria had also authorised the bear to be killed if necessary and that the search for the animal would continue on Wednesday. Germany's animal protection agency in Bavaria described as "hysterical" the decision to kill the bear.

Joern Ehlers, a spokesman for the World Wildlife Fund (WWF), told German radio that it was unusual for bears, normally shy animals, to seek out food in the vicinity of humans.

"The WWF is trying to catch the bear alive," Ehlers said. "Initially we wanted to tag it so we could better track its movements, but now it looks as if this bear cannot be left out in the wild because it's simply too dangerous."

Top-selling German daily Bild plastered a big picture of the bear with a hunter's bull's eye on it on its front page, alongside the headline "Death sentence for German bears!".

In a full page article, the paper showed gory pictures of disembowelled sheep alongside their concerned owners.

"It gutted them and then just ate their hearts and livers," the paper quoted 42-year old farmer Anton W. as saying.